Engine vibration - diagnosis?

I've been enjoying my 2000 VFR800 immensely since I got it this past winter.....put a couple thousand miles on it already due to the warm winter and unusually warm spring.  Overall the bike runs great, gets great gas mileage (average 47mpg), and is a blast to ride.

That said, I noticed from day one some vibration that I never had with my old gen2 VFR700.....I know that bike was a completely different beast, but it was smooth as silk and this new bike feels like a log wagon in comparison sometimes.  Here are the "symptoms"....

For starters, the bike runs/idles smoothly and pulls strong, however, when accelerating I feel a lumpiness or "chatter" vibration....almost what you would feel if the bike was in too high of a gear while trying to accelerate, but not that extreme. I feel the vibration in the bars and in the footpegs the most.  

The other time that it gets noticeable is when cruising (in any gear really) between 4500 and 5000 RPM.  The vibration almost feels like an out of balance wheel....but it definitely is not that....I can pull the clutch and coast at speed and the chassis is smooth as silk.....the vibration is definitely the engine/tranny.  This is unfortunate, because cruising at about 65-70 mph is right in that range.

The bike has roughly 16k miles on it.  It is due for the valve clearances checked right about now.  Other than an oil change and filter replacements, i've not touched the drivetrain since getting the bike this winter.  The chain and sprockets seem fine and the chain slack seems within spec.

This is my first Fuel Injected bike, so I'm unfamiliar with how these bikes normally run.  Is it possible that this is a starter valve synchronization issue?   Any other thoughts?

I had my '01 in to the dealer for something else and decided to have the valves adjusted, for the second time at about 70,000 mi. First one done at 20,000 and a check but no adjustment at 45,000. After the second valve adjustment I did notice the bike was running much smoother. I was not aware it was rough before the adjustment. Vibration just snuck up on me while I wasn't looking. There might be hope for you there.  

Sounds like the chain, that will definitely show up in the foot pegs.

Pull in the clutch at your cruising vib speed..let engine idle down...still vibrate? Not the engine then....Every time my chain gets worn  it starts a vib just like that..If it original, it could very well be shot..Grab a link half way around the rear sprocket and see if you can pull it outwards..much slack at all and its getting worn..new will be tight..also look close ,see if the orings are in there....good luck!

The chain and sprockets are in good shape and chain slack is within spec.  I have done exactly what you describe and the vibration was definitely engine and not chain/wheels.

This past weekend I performed the starter valve synch as laid out in the manual and it did improve things greatly in that 4500-5000 rpm range....still a bit of vibration, but not nearly as much as before.  The only vacuum gauge I have is part of a set of four (for carb synch) and it is in 25 mmHG increments, so once I get a more accurate gauge, I'll do it again and dial it in a bit more.  Honda certainly made the procedure simple by putting the vacuum tubes right up on the airbox!  It's a hell of alot easier than doing a carb synch on my old '74 CB550!

Thanks for the input guys!

[image: View Post]spud786, on 24 May 2012 - 05:16 PM, said:

Sounds like the chain, that will definitely show up in the foot pegs.

if your talking about the cam-chain, the 5th gens dont have one... there gear driven